Lang, A., Sparks, J. V., Bradley, S. D., Lee, S. K., & Wang, Z. (2004). Processing arousing information: Psychophysiological predictors of motivated attention [Abstract]. Psychophysiology, 41(Suppl. 1), S61.

Abstract
The present study continues the validation process of two self-report measures of motivational activation-Positivity Offset (PO) and Negativity Bias (NB). Cacciopo and colleagues have posited separate appetitive and aversive motivational systems with different activation functions. PO is the higher activation of the appetitive compared to the aversive system in a neutral environment while NB is the tendency for the aversive system to react more quickly than the appetitive system at a lower level of arousal. Previous research suggests that individuals can be separated into four motivational types by crossing PO and NB: coactives (high in PO and NB); risk takers (high PO/Low NB); risk avoiders (low PO/high NB); and inactives (low in PO and NB). It was predicted that HR deceleration and startle magnitude during slide viewing would vary as a function of NB and PO. Startle and EKG were measured in subjects of varying motivational activation while viewing 121 IAPS slides. Individuals with low NB bias exhibited larger magnitude startles compared to individuals with high NB. Individuals high in positivity offset showed greater heart rate deceleration in response to negative arousing slides compared to those with low positivity offset. All motivation types showed potentiated startles for negative arousing slides compared to positive arousing slides as would be expected.